Potassium Phosphate, Tribasic → Tert-butyl 4-cyclopropylpyridin-3-ylcarbamate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A pressure tube purged with nitrogen was charged with tert-butyl 4-iodopyridin-3-ylcarbamate (1.0 g, 3.12 mmol), potassium phosphate (2.393 g, 10.93 mmol), toluene (16 mL) and H2O (0.800 mL). The mixture was sparged with nitrogen for 20 minutes. Then cyclopropylboronic acid (0.349 g, 4.06 mmol), tricyclohexylphosphonium tetrafluoroborate (0.116 g, 0.312 mmol), and palladium(II) acetate (0.035 g, 0.156 mmol) were added, and the mixture was sparged with nitrogen for 15 minutes. The tube was closed with a pressure release valve top, and the mixture was heated at 100° C. for 20 hours. TLC (SiO2, 50% ethyl acetate/CH2Cl2) showed no starting material and a lower. Rf product. LCMS showed no starting material, and a large product peak, m/z 235. The reaction was cooled to room temperature, and the residue was taken up in ethyl acetate (100 mL), and washed with H2O (50 mL). The aqueous phase was re-extracted with ethyl acetate (50 mL), and the combined organic extracts were washed with brine (25 mL), dried over anhydrous MgSO4, filtered, and concentrated by rotary evaporation. The crude material was purified by SiO2 flash chromatography (2.5 cm×15 cm) eluting with CH2Cl2 to 6:4 ethyl acetate/CH2Cl2 to afford the product as a colorless viscous oil (634 mg).

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